Turret drills



Jan. 10, 1967 H. R. UHTENWOLDT IURRET DRILLS Original Filed Sept. 6,1960 3 Sheets-Sheet 1 INVENTOR HERBERT R. UHTENWOLDT fjdmi ATTORNEYSJan. 10, 1967 H. R. UHTENWOLDT 3,296,896

TURRET DRILLS Original Flled Sept. 6, 1960 3 sheets sheet 2 Jan. 10,1967 TURRET DRILLS Original Filed Sept. 6, 1960 H. R. UHTENWOLDT 5Sheets-Sheet 3 SOLENOIDS 12.3 4 IDDDQTS E zDDEs-i ADEEO Q t mAEDDPJ 050m mszzo D GEEEt-E United States Patent 3,296,896 TURRET DRILLS HerbertR. Uhtenwoldt, Worcester, Mass, assignor to Cincinnati Milling MachineCompany, Cincinnati, Ohio, a corporation of Uhio Original applicationSept. 6, 1960, Ser. No. 57,100, now Patent No. 3,173,315, dated Mar. 16,1965. Divided and this application (act. 9, 1964, Ser. No. 402,735 6Claims. (Cl. 7725) This application is a division of co-pendingapplication Serial No. 57,100 filed September 6, 1964, for Turret Drill,and now Patent No. 3,173,315, granted March 16, 1955.

This invention relates to an automatic turret drill and, moreparticularly, to a numerically controlled turret drill which willautomatically perform various machining operations on a workpiece morequickly and efficiently than has heretofore been possible with knowntypes of indexable turret drilling machines.

In a preferred embodiment of the invention, the machine is adapted to becontrolled from a tape containing information as to the tool to beselected, the type of operation to be performed such as tapping ordrilling, the X and Y coordinates of hole location, the depth of thehole being machined, and the spindle speeds and feeds to be employed asdescribed in Patent No. 3,173,- 315. The machine is provided with avertically movable drill head on which the turret is rotatably mounted.A plurality of radially extending tool spindles are provided on theturret for holding drills, taps, reamers, and similar tools, each ofwhich may be selectively brought into operative position by indexing theturret about its support on the drill head. The rotary positioning ofthe turret is effected by a hydraulic motor which is movable to aplurality of predetermined positions. After the turret is positioned, itis located and clamped by a hydraulically operated shot plunger andclamp piston.

Accordingly, it is an object of the present invention to provide a newand improved form of turret positioning, locating and clamping mechanismfor machine tools of the type in which any one of a plurality of rotarytools mounted on an indexable turret may be selected for operation.

With these and other objects in view, which will become apparent fromthe following description, the invention includes certain novel featuresof construction and combinations of parts, the essential elements ofwhich are set forth in the appended claims, a preferred form orembodiment of which will hereinafter be described with reference to thedrawings which accompany and form a part of this specification.

In the drawings:

FIG. 1 is a side elevation of a turret drill to which the presentinvention is shown applied.

FIG. 2 is a cross-sectional view taken along the line 22 in FIG. 1.

FIG. 3 is a diagrammatic view of the drill head and turret and includesthe hydraulic circuit utilized to operate the same.

FIG. 4 is a chart showing the turret positions corresponding to theenergization of the control solenoids.

The turret drill shown in FIGS. 1 to 4, inclusive, has a frame comprisedof a base 85 (FIG. 1) on which is supported a column 86. The forwardface of the column is provided with a pair of vertically extending ways87 (see also FIG. 2) on which the drill head 62 is supported by rolls 89for movement in a vertical direction. The drill head carries the turret63 which is supported on the head for rotation about a horizontal axis.In the present embodiment of the invention, the turret is fitted withsix radially extending spindles 45. The spindles are 3,296,896 PatentedJan. 10, 1967 journaled in bearings 92 (FIG. 2) fitted in apertures inthe turret, and each is adapted to hold a drill 93 or other suitabletool therein. Located beneath the turret on the base 85 is the table 28which is adapted to support the piece of work being machined. In thepresent embodiment, this table is adjusted in two mutually perpendiculardirections in a horizontal plane as indicated in FIG. 5. Thesedirections are hereinafter referred to as the X-axis and Y-axis, whilethe vertical adjustment of the head is referred to as the Z-axis. Thehead is arranged to be moved along the Ways 87 by a feed screw 95 whichis supported for rotation only in-a housing 96 secured to the upper endof the column 86. The screw meshes with a nut 97 secured to the drillhead so that when the screw is rotated, the head will be moved up ordown along the ways. Rotation of the screw is effected by the hydraulicmotor 59 (FIG. 3) driving a pinion 99 which meshes with a gear 101secured to the upper end of the screw. The motor is controlled by theservovalve 58 consisting of a piston type valve 102 and an electrictorque motor 103 for operating the valve. The motor and valve aresituated within the housing 96 as is also the feedback unit 86 which isdrivingly connected to the upper end of the screw 95.

The drive for the spindle 45 is provided by motor 46 which drives asplined shaft 109 journaled in the column 86 through electromagneticclutches 1CL to 6CL. These clutches may, for example, be of the MDO typemanufactured and sold by Warner Electric Brake & Clutch Co., of Beloit,Wisconsin. These are single acting, multiple disc clutches in which astationary field coil, when energized, causes a set of outer discs keyedto a driving cup to be pressed into engagement with a set of innerdiscs, keyed to a driven cone thereby coupling the cup to the cone. Whenthe field coil is deenergized, a return spring separates the disc anddisengages the cup from the cone. By virtue of the different gear ratiosemployed in the drive train, it is possible, by energizing the clutchesin various combinations, to obtain a considerable range of spindlespeeds. Additionally, as will be explained later, the motor 46 is wiredto operate at two different speeds so that a high range of spindlespeeds may be obtained and also a low range. The mot-or 46 also has adirect driving connection to the tachometer 48 which provides an AC.output that is utilized in a manner to be more fully explainedhereinafter.

The drill head has secured thereto a gear casing 110 within which issituated a helical gear 111 slida-ble along the splined shaft 109 whilebeing rotated therewith. The gear 111 meshes with a companion gear 112in the casing 110, which latter gear is fastened to a shaft 113journaled in the head. At its forward end, the shaft has fixed thereto agear 114 (FIG. 2) which meshes with a gear 115 attached to the rear endof a shaft 116 journaled in a sleeve 117 which is slidable in the head.The forward end of this shaft projects into the turret where it isfitted with a bevel gear 118. Inside of the turret each spindle 45 hassecured thereto a bevel gear 119 with which the gear 118 is adapted tomesh when the spindle is brought into operative position.

The turret is arranged to be indexed from any position to any otherposition under the control of solenoid operated valves as shown in FIG.3. It will be noted that the turret is provided with a tapered socketwhich receives the tapered end of a shaft 122 which is journaled in thedrill head 62. The turret is drawn snugly onto the end of the shaft by anut 123 and is held against rotation thereon by a key 124. At its rearend the shaft is fitted with a clamping piston 125 which works in acylinder 126 attached to the frame of the drill head. The shaft also hassecured thereto an elongated pinion 127 which meshes with a rack 128carried by a plunger 129 which forms part of the hydraulic motor 70 forindexing the turret. Cooperating with each end of the plunger areoperating pistons 130, 131, 132 and 133, which are received in cylinders134 and 135. The pistons 131 and 133 are bored to provide cylinders intowhich the smaller pistons 130 and 132 are fitted.

Pressure for operating the pistons is provided by a pump 138 which drawsfluid from a reservoir 139 and supplies it to a pump line 140 at apressure determined by the setting of a relief valve 141. Exhaust fluidfrom the motor and other parts of the system is returned to thereservoir through a line 142. The flow of pressure fluid from the line140 to the indexing pistons is controlled by valves 143, 144 and 145which are operated by solenoids ISOL, 2SOL, and 3SOL, respectively. InFIG. 3, the valves are shown in the positions they occupy when thesolenoids are deenergized. When the solenoids are energized, the valvesare moved toward the left as viewed in this figure. The chart in FIG. 4indicates which solenoids must be energized (E) and which must bedeenergized (D) for each position of the turret. When all threesolenoids are deenergized as shown in FIG. 3, the turret is moved tobring the #1 spindle 45 and its associated tool into operative positionas, for example, the drill 93 shown in FIG. 1. With the valves 143, 144and 145 in the positions shown, fluid under pressure will be supplied tomotor lines 146, 147 and 148. Pressure in line 148 will move the largepiston 133 up until it bottoms against the upper end of cylinder 135.This will, of course, carry the smaller piston 132 along with it.Pressure in the line 147 will flow into an elongated annular grooveformed in the piston 133 and thence through a port in the piston intothe interior thereof. Thus, fluid will enter the cylinder in whichpiston 132 is fitted and will move this piston up until it too bottomson the end of the cylinder 135. Pressure supplied through line 146 to acylinder 149 in which the plunger 129 works will force the plungerupward to the position shOWn. It will be observed that when pressure isconnected to motor lines 146, 147 and 148, the other group of motorlines 150, 151, and 152 will be connected to reservoir through line 142.Hence, the upper pistons 130 and 131 will collapse under the upwardthrust of the plunger 129. This is the first position of the turret.

When solenoid 3SOL is energized, pressure in line 152 will force piston131 down in the cylinder 134, and piston 133 will be released andpermitted to move down to the bottom of cylinder 135. This is the secondposition of the turret in which spindle #2 is moved into operativeposition. When solenoid 2SOL is also energized, pressure in line 151will force the piston 130 down, and piston 132 will be released andpermitted to move down in piston 133. This is the third position of theturret, in which spindle #3 is moved into operative position. Whensolenoid 1SOL is energized, and solenoids 2SOL and 3SOL are deenergized,pressure in cylinder 149 will be released, and pressure will be appliedto the upper end of the plunger. This will force the bottom end of theplunger against the piston 132 which will be held in the position shownin FIG. 3 by the pressure in lines 147 and 148. This is the fourthposition of the turret in which spindle #4 is moved into operativeposition. When solenoids 1SOL and 2SOL are energized, and solenoid 3SOLis deenergized, pressure will be applied to the upper end of plunger 129and to the piston 130 through lines 150 and 151. Also, piston 132 willbe released while piston 130 will be forced down. Pistons 131 and 133will assume the positions shown in FIG. 3, which is the fifth positionof the turret with spindle #5 moved into operative position. When allthree solenoids are energized, pressure in lines 150, 151 and 152 willapply pressure to pistons 130 and 131 and to the top of plunger 129.This will cause pistons 132 and 133 to collapse, and the plunger willassume its lowermost position, which is just the reverse of the positionshown in 4 FIG. 3. This is the sixth position of the turret in whichspindle #6 is moved into operative position.

Before the turret can be indexed, it must be unclamped and the bevelgear 118 withdrawn from engagement with the gear 119 on the spindle. Theengagement and disengagement of the bevel gears is effected by a pistonwhich works in a cylinder 154 in the drill head. The piston is attachedto a piston rod 156 which carries a shifting fork 157 for moving thesleeve 117 and gear 118 back and forth in the head. The iston alsooperates a locating pin 158 which seats in a recess formed in the turretto insure proper alignment of the turret in each position to which it ismoved.

When solenoid 4SOL is deenergized, as shown in FIG. 3, pressure fromline 140 is communicated by a line 159 to the rear of the piston 155.This maintains the bevel gear and locating pin in their forwardpositions. Pressure from the cylinder 154 is also communicated by anintermediate port therein to a line 160 which is connected to a pressureswitch lPS and also to the forward face of the clamping piston 125. Thiswill draw the shaft 122 rearwardly and clamp the turret against thedrill head. When solenoid 4SOL is energized, pressure from line 140 willbe delivered through a line 161 to the rear face of piston 125 tounclamp the turret and the forward end of cylinder 154 to disengage thebevel gear and locating pin. Pressure will also be cut off from line160, and the latter will be connected through a check valve 162 to thereservoir line 142. This will release pressure from the pressure switchlPS for a purpose which will be fully explained hereinafter.

In order to verify correct positioning of the turret 90 in accordancewith information supplied from the tape, the shaft 122 on which theturret is mounted is provided with a group of protuberances 163. Theseprotuberances are adapted to operate limit switches 1LS, 2LS, and 3L8situated within the head 62 as shown in FIG. 3. By utilizing differentcombinations of protuberances 163 in each of the six positions of theturret, it is possible to determine from the condition of the limitswitches whether the turret is in the position called for by the tape.More will be said about this feature of the control system in connectionwith the relay circuits which will hereinafter be described.

While in the foregoing description the invention was explained inconnection with one possible form or embodiment thereof whereforecertain specific terms and language have been used herein, it is to beunderstood that the present disclosure is illustrative rather thanrestrictive and that changes and modifications may be resorted towithout departing from the spirit of the invention as defined by theclaims which follow.

What is claimed is:

1. A locating and clamping mechanism for a tool turret movable to aplurality of index positions comprising a frame, a shaft supported forrotary and axial movement in said frame, a turret fixed on said shaftfor movement therewith, said turret having a locating recess therein foreach index position, a piston motor connected to said shaft foreffecting axial movement thereof to clamp and unclamp the turret, ahydraulically operated plunger mounted in said frame for axial movementinto and out of engagement with the locating recesses in said turret, avalve for controlling the operation of said plunger, and a hydrauliccircuit controlled by portions on said plunger as it moves intoengagement with a locating recess in said turret for energizing saidpiston motor and clamping said turret.

2. The locating and clamping mechanism of claim 1 including a toolspindle in said turret, a driven gear on said spindle, a drive gearsupported on said frame for sliding movement into and out of engagementwith said driven gear, and means operated by said plunger as it movesinto engagement with a locating recess in said turret for moving saiddrive gear into engagement with said driven gear whereby a drivingconnection will be provided to the tool spindle when the turret islocated and clamped.

3. A machine tool having a frame, a work support carried by said frame,a tool support mounted on said frame for movement relative to said worksupport, a turret mounted on said tool support for rotation about acentral axis, a plurality of tool spindles journaled in said turret forrotation about axes spaced about and diverging from said central axis, aspindle drive mechanism including a drive gear carried by said frame anda driven gear on each of said spindles adapted to mesh with said drivegear when its associated spindle is moved into operative position, andmeans for indexing said turret about its axis to a plurality ofoperative positions each of which coincides with an operative positionof one of said tool spindles, said indexing means including areciprocatory motor movable to a plurality of predetermined positionsfor rotating said turret directly from one operative position to anyother operative position, and selectively operable means for controllingthe rotation of said turret by said motor so as to move a selected oneof the tool spindles into operative position.

4. The machine tool of claim 3 wherein said motor is a linear hydraulicmotor having an output member movable directly from one of a pluralityof predetermined positions to any other of said plurality ofpredetermined positions, and including means for drivingly connectingsaid output member to said turret.

5. The machine tool of claim 4 wherein said last-mentioned meansincludes a rack on said output member and a pinion connected to saidturret and meshing with said rack.

6. The machine tool of claim 5 including mean for moving said turret andsaid pinion relative to said tool support and said rack in the directionof said central axis so as to disengage said drive and driven gearswithout disturbing the meshing relationship of said rack and pinionprior to indexing of said turret by said motor.

References Cited by the Examiner UNITED STATES PATENTS 2,952,169 9/1960Johnson 74826 XR FRANCIS S. HUSAR, Primary Examiner.

1. A LOCATING AND CLAMPING MECHANISM FOR A TOOL TURRET MOVABLE TO APLURALITY OF INDEX POSITIONS COMPRISING A FRAME, A SHAFT SUPPORTED FORROTARY AND AXIAL MOVEMENT IN SAID FRAME, A TURRET FIXED ON SAID SHAFTFOR MOVEMENT THEREWITH, SAID TURRET HAVING A LOCATING RECESS THEREIN FOREACH INDEX POSITION, A PISTON MOTOR CONNECTED TO SAID SHAFT FOREFFECTING AXIAL MOVEMENT THEREOF TO CLAMP AND UNCLAMP THE TURRET, AHYDRAULICALLY OPERATED PLUNGER MOUNTED IN SAID FRAME FOR AXIAL MOVEMENTINTO AND OUT OF ENGAGEMENT WITH THE LOCATING RECESSES IN SAID TURRET, AVALVE FOR CONTROLLING THE OPERATION OF SAID PLUNGER, AND A HYDRAULICCIRCUIT CONTROLLED BY PORTIONS ON SAID PLUNGER AS IT MOVES INTOENGAGEMENT WITH A LOCATING